Aviation materials and tecnologes №4, 2010

Increase of reliability of power IGBT-modulus by means of high filled metal matrix composite of Al-SiC system

Main factor of providing the maximal productivity of semi-conductor devices is efficiency of heat transfer from a crystal to the heat-carrier, characterized by thermal resistance. From the point of view of thermal processes, power packs can reliably function on the understanding that there is an effective heat rejection. In a complex multilayered structure for heat rejection the heat-rejecting substrates are of prime importance. It is especially actual at growing need for new power semi-conductor devices where the heat-rejecting substrates should possess high heat conductivity and low factor of thermal expansion.

Effect of the thermomechanical treatment on Al (Al-Cu-Mg-Li-Zn) alloy properties and structure

The high-strength weldable corrosion-resistant B-1461 (Al-Cu-Mg-Li-Zn (Zr, Sc)) alloy is related to the last generation of Al-Li alloys and it's characterized by the decreased Li content, high technological efficiency and cracking resistance characteristics. The effect of thermomechanical treatments, multi-stage ageing conditions on the structure and properties of B-1461 alloy is considered in the present paper.

Microporosity of the single-crystal castings produced of carbon-free superalloys

The study of the microporosity of the single-crystal castings for turbine blades, produced of carbon-free superalloys (ЖС36, ВЖМ5 types), was conducted along with the development of technological methods for the microporosity reduction or its complete elimination during the alloy structure formation process by the directional or highly directional solidification methods.

Test methods of structural composites with the integrated electromechanical system

Some specific aspects have been considered when studying the properties of composites with integrated actuatoring systems. The description of the special equipment such as the spectrometer for determining the characteristics of fiber-optical Bragg lattices and lazer three-angel measuring system is given for studying the appearance and changes of strain-stress state as well as the geometric changes of a structural composite specimen shape.

Thermoelastoplastics - a new class of polymer materials

The service properties of two types of thermoelastoplastics, developed in VIAM FSUE and entirely meeting АП-25 requirements on combustibility are considered in the present article. These materials are as follows:
- ВТЭП 1-Л type - with the increased weather resestance;
- ВТЭП 2-Л type - with the improved electroinsulation characteristics.
The developed materials are processed into products by the injection molding method and recommended for the partial rubber substitution.

Some methodical aspects of natural climatic tests of polymer composites were considered on the example of СТ-2227М glassfiber reinforced plastic (GFRP). The full-scale climatic ageing was carried out under the open weather conditions and the shed. The tests were performed according to GOST 9.708 requirements at the climatic station, situated in the temperate climatic zone with the industrial atmosphere (Moscow city). The material mechanical properties were determined along with its macro- or microstructure throughout four-year exposure. It was stated, that it's necessary to define the moisture-saturation value of an exposed specimen as well as the strength of moistered and dried tested material specimen with the goal of studying and determining the possible irreversible processes in the polymer matrix due to the climatic factors effect during the full-scale exposure.